Prove thatf −1(G ∪ H) = f −1(G) ∪ f −1(H)
Question
Prove thatf −1(G ∪ H) = f −1(G) ∪ f −1(H)
Solution
To prove that f^−1(G ∪ H) = f^−1(G) ∪ f^−1(H), we need to show that each set is a subset of the other.
Step 1: Show that f^−1(G ∪ H) is a subset of f^−1(G) ∪ f^−1(H)
Let x be an arbitrary element of f^−1(G ∪ H). This means that f(x) is in G ∪ H. Therefore, f(x) is in G or f(x) is in H. If f(x) is in G, then x is in f^−1(G). If f(x) is in H, then x is in f^−1(H). In either case, x is in f^−1(G) ∪ f^−1(H). Since x was an arbitrary element of f^−1(G ∪ H), we can conclude that f^−1(G ∪ H) is a subset of f^−1(G) ∪ f^−1(H).
Step 2: Show that f^−1(G) ∪ f^−1(H) is a subset of f^−1(G ∪ H)
Let x be an arbitrary element of f^−1(G) ∪ f^−1(H). This means that x is in f^−1(G) or x is in f^−1(H). If x is in f^−1(G), then f(x) is in G. If x is in f^−1(H), then f(x) is in H. In either case, f(x) is in G ∪ H, which means that x is in f^−1(G ∪ H). Since x was an arbitrary element of f^−1(G) ∪ f^−1(H), we can conclude that f^−1(G) ∪ f^−1(H) is a subset of f^−1(G ∪ H).
Since we have shown that each set is a subset of the other, we can conclude that f^−1(G ∪ H) = f^−1(G) ∪ f^−1(H).
Similar Questions
Prove thatf −1(G ∩ H) = f −1(G) ∩ f −1(H)
Let f(x) and g (x) be one-to-one functions, and let h (x) = g ( f(x)). Show that the inverse functionof h (x) is h^−1 (x) = f^ −1(g^−1 (x))
(ii) Prove thatf (E ∪ F ) = f (E) ∪ f (F )
Prove or disprove that (A ∪ B) − B = A − B for any sets A and B.
Let f : X → Y and g : Y → X. If g ◦ f is an identity function on X and f ◦ g is an identityfunction on Y , then, show that(a) f is one-one(b) f is onto(c) g = f −1
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.